1. Field of the Invention
The present invention relates to an electrosurgical apparatus for treating biological tissue and a method for controlling the electrosurgical apparatus, and more particularly to an electrosurgical apparatus for joining biological tissues and a method for controlling the electrosurgical apparatus.
2. Description of Related Art
Electrosurgical apparatuses are already widely used for surgical operations and the like. For example, electrosurgical apparatus are utilized in surgical operations to perform treatment such as dissecting biological tissue or joining tissues that have been dissected.
More specifically, a treatment instrument connected to a high frequency power source is brought in contact with the biological tissue that is the treatment target so that a high frequency power from the high frequency power source is supplied to the treatment instrument to thereby dissect or join the tissue that is the treatment target.
This kind of electrosurgical apparatus has already been proposed in various publications. For example, Japanese Patent Application Laid-Open Publication No. 8-98845 or Japanese Patent Application Laid-Open Publication No. 2002-325772 proposes an electrosurgical apparatus that is designed to prevent carbonization of coagulating biological tissue, determine the end of coagulation based on the impedance of the biological tissue, and then stop the high-frequency output.